Anyone know what this could be? *update*

My LO had this on his face this morning. It’s not a raised bump or anything just this circle. It faded away slightly about 30 minutes later, but he’s with a sitter today so I won’t personally be able to monitor it.

Anyone ever see anything like it? He doesn’t have anything in bed with him that could leave a mark like that, that’s why I’m concerned. I searched around the whole area just in case and didn’t find anything like that.

*update* after it faded away in the morning it did not come back. Still trying to figure out what could have left that imprint 🤷‍♀️ thank you everyone for the advice and input!